Reversing gear



Dec. 7, 1948. I G. B-ARRETT 4 REVERSING GEAR Filed Jan. 30, 1945 2sheets-sheet 1 g1 Z7 Z5 G. BARRETT REVERSING GEAR Dec. 7 1948..

2 Sheets-Sheet 2 Filed Jan. so, 1946 Patented Dec. 7,1948 r UNITEDSTA ESi 1 i I t I nevansmo h Guy BarretLBosham, near ChichesterQEngland,assignor toWyclifie Foundry .& Engineering Company Limited,Lutterw'orth, Leicestershire,

England i Applicationlanuaryw,1946,SerialNof644,313

InGreatBritaln November 8,1944 y i This invention relates to reversinggears f op: tionally in association with change speedgears of the kindenabling a change of direction of retation of adriven shaft with respectto a driving shaft and in the caseof constructions embodying a. changespeed gear an alteration in the ratio of speed oi rotation of the driven-shaft with respect to the driving shaft to be made! The object oftheinvention is broadly stated to provide a construction ofreversinggearwith which optionally may be associated a change speed gearto provide adrive in the forward or reverse a ciiims. (01. 74-1377)element li and withthe other of these a do clutch element lifleach ofthese dog clutch elements being in permanent driving connection withiitsrespective pinion. l i With one of these dog clutch elements there isassociatedan"axially displaceable dog c1utchl3 secured from rotationrelative to the shaft by the feather: I4 and with the dog clutch elementI2 direction ofa positive characterand thusavoid ing the employment ofequivalents; i l

A particular objectof the *invention is to provide a construction :ofreversing gear associated triction clutches or their there is arrangedto co-operate a dog clutch element I5 slidable along theshaft butsecured from rotationfrelative thereto by the feather l6 so thatadrivingconnection between one orother of the pinions on the driven shaftmay be secured i With the driving and driven shafts there are associatedtwo lay shafts ll and I 8,the former with a change speed gear of'xthezkind in which Figure l is alongitudinal view in sectionalelevation of agear boxeinbodying a reversinglgear On the shaft inquestionandspacediromthis pinion by a collar 9 is afsecond pinion l0 rotatable onthe shaft but secured fromjaxial motion withrespectthereto. i 1 w w: 5*;

With the latter of these pinions and'secured from axial motion 5 on the1 shaft is a dog clutch motion-with respect thereto,

being altubular shaft rotatably mountedin roller bearings 19,1and ballbearings in the standards 22 andil provided in the casing |,the otherlay shaft -being rotatably secured in roller bearings 23andba1lbearings24 providedin the ends of thecasingfl: 1 1 i On onewof the lay shafts,namely,the shaft I8, thereyis provided apinion 25in permanent engagementwiththe pinion 8, the pinion 25 being provided internally with ahemispherical projection 25 engaging a correspondingly formed recess inthe shaft l 8zto permit a limited degree of mo tion of thepinion aboutan axis perpendicular to the axis of: theshaft, while on the tubularshaft li'lwthere is similarly arranged a pinion 21 in permanent driving;connection with apinion 21a, see

Figure 2, on a lay shaftflb and this pinion in i turn is inpermanentdriving engagement with the pinion l0. 1 a

,"On thelay shaft ll there is also provided a toothed pinion 2 8furnisheduwithla hemispherical eIe mentjZB engaging a sock et on itsshaft and in permanent driving engagement therewith, while on the shaft18 there is provided a toothed wheel 30 similarly provided with ahemispherical element 3 I by which it is engagedin permanentdrivingconnectionwith its shaft.

, Bothof these toothedwheels are secured from axial motion with respectto their shafts and they are of the following form, that is to say, theyareof conical form and are such as are provided in; change speed gearsoithe type described in British specifications 1510s., 331,292; 529,506;539,062 and 557,941, andthey are positioned so that one or other of suchwheels may be engaged by a pinion32 slidably mounted upon the drivingshaft; 2 but secured from rotation relative thereto by the feather 33and on the pinion in question theliewis provided acollar 34 for movingitinto and out of engagement with the toothed wheels 30 and 28, the lengthof the face of the pinion being such that in its passage from fullengagement with one pinion into engagement with the other pinoin therewill be an interval during which time botho'f such: piniohswill'be'engaged by it. I 4

When the whee] 32 is fully engaged with the toothed wheel 30, butdisengaged from the pinion 28, a forward drive is secured whereas whenthe toothed wheel 32 is in full engagement with a" toothed wheel 28 butdisenggaedfromthe Wheel- 30, a drive in the reverse sense isisecured.The toothed wheel 32 and'the dog-clutch ele-' ments [3 and I areassociated with means whereby motion is imparted to them si multanmously so that the following operations are se cured in the sequencestated, namely, disengageadapted to secure simultaneous axialdisplacement; of the pinion slidably mounted on the driving shaft andthe dog clutch elements slidablymoimted on the driven shaft to secure inchanging from forward to reverse the fol- '-lowing-operations in thesequence stated: disengagement of-the slidable dog clutch element co-;operating with the dog clutch element of the firstementioned pinionrotatably mounted on the merit of the slidable dog clutchelemerltl-5-b8- operating with the dog clutch element I2 of the pinion 8prior to the engagement -of,-thea-other slidably mounted dog clutchelementli-yvith the dog clutch element I! of the pinion H3 on the drivenshaft and prior tothe disengagementof the pinion 32 from the pinion-',thattis' in changin from the forward to reverse andrcon versely inchanging from'reverse to forward; Preferably; there is provided meansadapted also to actuate brake shoes 35 or a'brake band co-operating witha'lo'rake. drum 31 on the :driven shaft so'that a braking effect issecured :on'the drivenshaft before the *dog cIutch elements' 43 or I 5slidable thereon and whichco-operate'with the dog clutch elements I! andE5 in permanent driving connection with the toothed wheel vare fullyengaged therewith and as above indicated: This sequence ofoperationsimay' he understood more clearly by reference to Figuress3,'4,5; 6 and 7 in whichFigure 3 showslth'e severalielements including thebraking: mechanism. in, a position for securing a forward idrivqFi'gure4:.illustrat''s the elements in a position in which theufonward drive isabout to be interrupted, Figure 5 illustrating the position of'theelemnts when the pinion 32 is simultaneously in engagement with thetoothed wheels 29 andSB anduthe-idog'oliitch elements I3 and 15 arefully disengaged, the brake :being fully applied, andifilgure 6 showstheseveral elements in position whenthe pinion -32 is in full drivingengagement with the wheel 23 but is disengaged from the toothed wheel 30and thedog clutchrelement'lt is about to engage the dogclutch element H..111 this position the commencement bf" theme lease of the brake takesplace. I Following'upon this tns ve rai elements are brought into theposition shown'in figure rwhere' the dog clutch element I3 is in fullengagemen with the dog clutch element ll toj'eifec't a drive in reverse.1

m m p l; A reversing gear c6ml r 1ng a" driving and a d i e h f a rangej oa l v amien o en a pinion rotatably "mounted on the driven shaft butsecured from axial motion with respect thereto; a second pinion alsorotatably mounted on the drivenshaft but se ure rrqm axial mm tion withrespect thereto and in =p'e'rmanent driv; ing connection with each ofthesefpinionsand secured from axial motion a dog clutch element, witheaoh of which an axially displaceable dog clutchel'ement rotatable withthe driven shaft isassociated to establish a driv'in'g'co'nnectionbetween its related pinion-and the driven shaft, two My shafts eachfurnished witha toothed driven shaft prior to the engagement of theother slidab y mounted dog clutch element with the second-mentionedpinion mounted on the driven shaft and prior tio'the disengagement ofthe pinion'slidably mounted-on the driving shaft fro'm the toothed wheelmounted on the lay shaft which isin permanent driving connection withthe fns't mentioned pinion and conversely in changing from reverse toforward. I

2. Awreversing gear comprising a driving and a driven shaft arrangedcoaxially and end to end, a. lay shaft, a toothedwheel on the lay shaftin driving connection with a pinion rotatably mounted on'the drivenshaft but secured from axial motion with respect thereto, a dog-clutchelement rotatable 011112118 driven shaft and in permanent drivingconnection with the pinion, a dog clutch element on the driven shaftslidable thereon but secured from rotation relative thereto adaptedto-engage withiand to be disengaged from the dog clutch elementrotatable onthe driven shaft and in permanent driving connection: withthe pinion, a tubular lay shaft sur rounding thelfirstmentioned layshaft, a toothed wheelon the tubular shaft, an idler wheel in enagementtherewith', and in engagement with the idler wheel apinion rotatablymounted on" but secured from axial motion with respect to the drivenshaft,--a dog clutch element rotatable on the shaft and; in permanentdriving connectionwith this pinion, a dog clutch element mounted onthe.driven; shaft secured from rotation relative thereto but sli'clableaxially along it to bring; into and-out ofengagement'with the dogclutchelement rotatable on itss'haft and in permanent driving connectionwiththis'pinion, on the'lay shaft a toothed wheel and on the tubular shaft atoothedfiwheel at a position adjacent to the toothed wheel on thelay'shaft andon the driving shaftpermanently secured from rotationrelative thereto; but slldable axially-thereon to bring it out. of andinto driving engagement with the toothed wheelon the layv shaft and intoand out of engagement with the toothed wheel on the tubular shaft toprovide in the former case a forward drive and in the latter case adrive in reverseo'f the driven shaft, and means adapted tosecuresimuitaneous axial displacement of the pinion slidably mounted onthe driving shaft and the dogfcltitch elements slid-ably mounted on thedriven'shaftto secure in changing from forward ment of theother'slidably mounted dog clutch element -tvith' the second mentionedpinion 5 a mounted on the driven shaft and prior to thedisengagement ofthe pinion slidably mounted on the driving shaft from the toothed wheelmounted on the lay shaft which is in permanent driving connectidn withthe first-mentioned pinion and conversely in changing fromreverse" toforward.

3. A reversing gear as claimed in claim 1' in which the width of theface of the pinion siidably mounted on the driving shaft and thepositions of the toothed wheels with which it co-operates on the layshafts is such that in its displacement the pinion will temporarily bein driving engagement with both of such wheels before the dog clutchelement slidably mounted on the driven shaft is brought into engagementwith the dog clutch element of the second-mentioned pinion.

4. A reversing gear as claimed in claim 1 in which the means adapted toimpart motion to the clutch element in permanent driving connection withthe second-mentioned pinion is fully engaged therewith. t

5. A reversing gear as claimed in claim 1 in which to facilitateengagement of the pinion slidably mounted on a) driven shaft with thetoothed wheels on the lay shafts, and further to facilitatesuchengagement the side faces or edges of the teeth on the wheels arebevelled, chamfered or rounded.

6. A reversing gear as claimed in claim 1 in. which the side faces oredges of the slidable pinion are also bevelled; chamfered or rounded.

'7. A reversing gear as claimed in claim 1 iii which the axes of the layshafts are inclined with respect to the common axis of the driving andthe driven shafts, and in which the wheels on the lay shafts areconical.

GUY BARRETT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,269,944 Leonard June 18, 19182,344,046 Le Tourneau Mar. 14, 1944

